Means for eliminating disturbing noises



July 28, 1925.

R. A. FESSENDEN MEANS FOR ELIMINATING- DISTURBINC- NOISES Original Filed Aug. 20.- 1317 Patented July 28, 1925.

* UNITED STATES '-1, s41.74o PATENT OFFICE.

REGINALD A. FESSENDEN, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR TO SUBI IA RINE SIGNAL COMFANY, OF PORTLAND, MAINE, A CORPORATION OF MAINE.

MEANS FOR ELIMIQN'ATING DISTURBING NOISES.

Original application flied August 20, 1917, Serial No. 187,121. Divided, and this application iiled 7, 1918. Serial No. 253,102.

To all whom it may concern: Be it known that I, REGINALD A. FESSEN- DEN, of Brookline, in the county of Norfolk and State of Massachusetts, a citizen of the United States, have invented a new and useful Improvement in Means for Eliminfluences. and water noises, such as cause disturbancein submarine signaling and detecting submarines. V

The object of my invention 1s to obtam increased eflicienc in these lines.

This case is a ivision of application Serial7 No. 187,121, filed by me August 20, 191

The drawing shows diagrammatically apparatus embodying my invention.

The drawing shows a means for eliminating disturbing noises, the utility of WhlOh is based upon the discovery made by applicant that if a number of receiving mechanisms are connected in parallel with each other and preferably in one plane and in series with the receiver, water and other disturbing noises will be practically eliminated and the onl' sounds received without diminution will e those enerated at a distance from the plane 0 the receiving 1 mechanisms and at a point perpendicular to the plane of the receiving mechanisms.

For example, 40 is adiaphragm, which may be'merely a-supporting surface and say two feet in diameter; 30, 30, 30 are m'- 3 ertia microphone buttons or magnetophones circuit attached to the diaphragm 40, as shown, and connected in parallel with each other and in series with the receiver 34 by the leads 31, 32. 33 is a battery.

' Water noises or other disturbing local noises will not reach a microphone all at the same instant and. consequently the changes in current in the different microphones will be of different phases and consequentl each microphone will be shortthe diaphragm at an angle, since the sound asregards those noises by all the will reach the diaphragm on the near edge before it reaches the diaphragm on the far edge. Consequently, the sounds arriving from the side will be weakened. But'sounds arriving normally to the diaphragm will actuate all the microphones or magnetophones at the same instant, and consequently September the indication produced on the recelver 34 will be a maximum.

Consequently, in the type of apparatus shown not only are disturbing noises reduced to a minimum but there is also a strong directional efi'ect.

What I claim as my invention is 1. Apparatus for the receipt of si als comprising both desired and undesire impulses and for eliminating the disturbing effect of undesired si als and noises comprising a plurality'o receivers operatively connected to act simultaneously and conjointly and located in a sound-transmitting medium and at such large distance from each other and so oriented that the'impulses produced in the medium by undesired signals and disturbing noises will impress their effects upon said receivers located at a dis-. tance from each other in different and opposing phases; and the impulses produced in the medium by the desired signals will impress their effects in the same phase; whereby the efl'ect of said undesired signals and disturbing noises is minimized; and an indicating mechanism operatively connected toall of said receivers whereby the desired signals may be detected.

2. Apparatus for the receipt of signals comprising both desired and undesired impulses and for eliminating the disturbing effect of undesired si als and noises comprising a plurality o i'eceivers operatively connected to act simultaneously and conjointly and located in a sound-transmitting medium and on a common surface, said common surface being of such large dimensions that the impulses produced in the medium by undesired signals and disturbing noises will impress their effects on said receivers located on difl'erent parts of the common surface in different and opposing phases; whereby the effect of said undesired signals and disturbing noises is minimized; and an indicating mechanism operatively connected signals may be detected.

turbing noises will impress their effects on said receivers located on different parts of the common surface in different and opposin phases; whereby the effect of said undesired signals and disturbing noises is minimized; and an indicating mechanism operatively connected to all of said receivers whereby the desired signals may be detected.

4. Apparatus for the receipt of signals comprising both desired and undesired impulses and for eliminating the disturbing effect of undesired -si als and noises comprising a plurality o receivers operatively connected to act simultaneously and conjointly and locatedin asound-transmitting medium and on a common surface, said common surface being of such lar e dimensions and so oriented that the impu ses produced in the medium by undesired signals and disturbing noises will impress their effects on said receivers located on different arts of the common surface in difierent an opposing phases; and impulses produced by the desired si als will lmpress their effects on said recelvers in similar and assisting phases, and an indicating mechanism operatively connected to all of said receivers whereby said desired signals may be detected.

5. Apparatus for the recei t of signals and for eliminating the disturbing effect of undesired signals and noises comprising a plurality of receivers, operativel connected to act simultaneously and con oint1y and said receivers being connected in parallel with each other and located in a soundtransmitting medium and at such large distance from each other and so oriented that the impulses produced in the medium by undesired signals and disturbing noises will impresstheir effects upon said receivers located at a distance from each other in different and opposing phases; and the impulses produced in the medium by the desired signals will impress their effects in the same phase; whereby the effect of said undesired signals and disturbing noises'is minimized; and an indicating mechanism operatlvel connected to said recelvers whereby t e desired si als may be detected.

6. Apparatus for ti: recei t of signals and for eliminating the disturbing effect of undesired signals and noises comprising a plurality of receivers, operatively connected to act simultaneously and con ointly and said receivers being connected in'parallel with each other andlocated in a soundtransmitting medium and on a common surface, said common surface being of such large dimensions that the impulses produced in the medium by undesired signals and disturbing noises will impress their effects on said receivers located on different parts of the common surface in different and opposing phases; whereby the effect of said undeslred signals and, disturbing noises is minimized; and an indicating mechanism operatively connected to said receivers whereby the desired signals may be detected.

7. Apparatus for the receipt of signals comprising both desired and undesired impulses and for eliminating the disturbing effect of undesired signals and noises comprising a plurality of receivers operatively connected to act simultaneously and conjointly and located in a sound-transmitting medium and at such large distance from each other and so oriented that the impulses produced in the medium b undesired signals and disturbing noises Wlll impress their effects upon said receivers located at a distance from each other in different and opposing phases; and the impulses produced in the medium biry the desired signalswill impress their e ects in the same phase; whereby the effect of said undesired signals and disturbing noises is minimized.

8. Apparatus for the receipt of signals comprising both desired and undesired impulses and for eliminating the disturbing effect of undesired signals and noises comprising a plurality of receivers mounted on a common surface operatively connected to act simultaneously and conjomtly and located in a sound-transmitting medium and said common surface being of such large imen sions that the impulses produced in he medium by undesired signals and disturbing noises will impress their effects on said reproduced in the medium by undesi s1g-. nals and disturbing noises will impress their effects on said receivers located on difierentr parts of the common surface in different and =opposing phases, whereby the effect of said undesired signals and disturbing noises is minimized. Y

10. Apparatus for the receipt of signals comprisin both desired and undesired impulses an for eliminating the disturbing effect of undesired signals and noises comprising a plurality of receivers mounted on a common surface operatively connected to act simultaneously and conjointly and located' in a sound-transmitting medium and said common surface being of such large dimensions and so oriented that the impulses produced in the medium by undesired si nals and disturbing noises will impress their effects on said receivers located on difl'erent parts ofthe common surface in different and o posing phases; and impulses produced by t e desire signals will impress their effects on said receivers in similar and assisting phases. 1

11. Apparatus for the receipt of signals and for eliminating the disturbing efl'ect 0f undesired signals and noises comprising a plurality of receivers operatively connected to act simultaneously and conjointly, said receivers being connected in parallel with each other. and located in a sound-transmitting medium and at-such large distance from undesired signals and noises comprising a plurality of receivers, operatively connected to act simultaneously and conjointly, said receivers being connected in a parallel with each other and located in a sound-transmitting medium and on a common surface, said common surface being of such large dimensions that the impulses produced in the medium by undesired signals and disturbing noises will impress their efi'ects on said receivers located on difl'erent parts of the common surface in different and opposing phases; whereby the efl'ect of said undesired signals and disturbing noises is minimized.

REGI'NALD A. FESSENDEN. 

